Backend Skript not executed

[Rüdiger Müller]

Hello all helpfull people,

if Cups starts the Backend it holds this Process and does not execute it.

Output from ps -xa:

 3648 ?        R      0:00 /bin/bash /usr/lib/cups/backend/an_drucken_aus.sh 78 guest Test Page 1 job-uuid=urn:uuid:55db99d8-092f-3c72-54d3-48cd8a54f730

I do not know why this happens. The script contains a root-statement (switch a electr. socket of an USB-Device on, then wait till no job is in /var/spool/cups, and then switch socket off.), but my user cupsys is in the root-group.

The script could be more elegant for sure. I add it at the end.

So my problem is that the script is executable from command-line with user cupsys, but does not execute when called from within cups.


Version 0.001
---
Script for switching a (Printer)-Socket on before printing, and switching it off when all jobs in /var/spool/cups deleted.


#!/bin/bash

#Diagnose
#If Cups start the script there is no output in the ./whoami file
whoami >> ./whoami



#Parameter
typeset -r jobhdatei="c000"$1

#Constants
typeset -r spooldir="/var/spool/cups"
#Zeit
typeset -i -r nachlaufzeit=5
typeset -i -r zeiteinheit=1


function An()
{
  /usr/bin/sispmctl -o 1
  typeset -i paus=0
  typeset -i weiter=1
  while [ $weiter -eq 1 ] ;
  do
    if [ -e /dev/usb/lp0 ] ;
      then
        echo "An"
        weiter=0
      else
        sleep $paus
        weiter=1
    fi
  done
  return
}

function Aus()
{
  /usr/bin/sispmctl -f 1
  echo "Aus"
  return
}
function Drucken()
{
  echo "Drucken"
  function JobFertig()
  {
    if [ -e $spooldir/$jobhdatei ] ;
   then
      return 0
    else
      #Datei gel., fertig
      return 1
    fi
  }
  typeset -i zeit=$nachlaufzeit
  function ZeitAbgelaufen()
  {
    if [ $zeit -le 0 ] ;
    then
      return 1
    else
      return 0
    fi
  }
  function ZeitLaeuft()
  {
    sleep $zeiteinheit
    zeit=`expr $zeit - $zeiteinheit`
    return
  }
 typeset -i paus=0
  typeset -i fertig=0
  while [ $fertig -eq 0 ] ;
    do
      JobFertig
      fertig=$?
      sleep $paus
      echo "Sleeping"
  done
  typeset -i abgelaufen=0
  while [ $abgelaufen -eq 0 ] ;
    do
      ZeitLaeuft
      ZeitAbgelaufen
      abgelaufen=$?
      echo "Nachlauf"
  done
  function WeitereJobs()
  {
    typeset -i anzahl=`ls -l $spooldir | wc -l`
    anzahl=`expr $anzahl - 2`
    return $anzahl
  }
 WeitereJobs
  typeset -i weitere=$?
  if [ $weitere -eq 0 ] ;
  then
    Aus
    return 1
  else
    return 0
  fi
}


if [ $# = 0 ]
  then
    echo "SIS-PM \"SIS-PM Powered Printer\" \"SIS-PM Printer Port\""
    exit 0
fi


An
Drucken >> druck_log&

#Usage: usb job-id user title copies options [file]
export DEVICE_URI="usb://Brother/MFC-8420"
exec -a ${DEVICE_URI} /usr/lib/cups/backend/usb "$@"